#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif

#define _USE_MATH_DEFINES
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
//https://boostjp.github.io/tips/multiprec-int.html
using lll = __int128_t;

#define YES cout<<"Yes\n"
#define NO cout<<"No\n"
#define YN {cout<<"Yes\n";}else{cout<<"No\n";}// if(a==b)YN;
#define NO2 cout<<"-1\n"

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rrep(i, n) for (int i=int(n)-1; i>=0; --i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()

void solve() {
    ll N,M;
    cin>>N>>M;
    vector<ll> A(M), B(M);
    rep(i,M) cin >> A[i] >> B[i];

    if (M==1) {
        if (B[0] == N) YES;
        else NO;
    }
    else if (M==N) {
        bool flag = true;
        rep(i,M) {
            if (B[i] != 1) {
                flag = false;
                break;
            }
        }
        if (flag) YES;
        else NO;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int T;
    cin >> T;
    while(T--) {
        solve();
    }
}